* {
    margin: 0;
    padding: 0;
}
body {
    background-color: #efefef;
}
li {
    list-style-type: none;
}
a {
    color:#000;
    text-decoration-line: none;
}
a:hover {
    color: brown;
    text-decoration-line: underline;
}
/*********** 声明顶部样式 ***********/
header {
    background: linear-gradient(to top, lightgrey, #efefef);
    margin: 10px 20px;
    overflow: hidden;
    height: 60px;
    border-bottom-left-radius: 20px;
    border-bottom-right-radius: 6px;}
header div {
    width: 1200px;
    margin: auto;
}
header h1 {
    float: left;
    margin-left: 20px;
    font-weight: normal;
    line-height: 60px;
}
header nav {
    float: right;
    margin-right: 20px;
}
header nav ul li {
    float: left;
    padding-left: 30px;
    line-height: 80px;
}
/*********** 声明主体区样式 ***********/
/*侧边导航栏*/
main {
    width: 1000px;  /*内容区宽度*/
    height: 800px;
    margin: 30px auto 0;
    padding-left: 200px;
    overflow: hidden;
    /*布局参考线*/
    /*border: 1px solid red;*/
}
main article {
    float: left;
    /*布局参考色块*/
    /*background-color: #FD6FCF;*/
    width: 100%;
    min-height: 100%;
    background: linear-gradient(to bottom, lightgrey, #ededed);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1);
    border-radius: 6px;
}
main aside {
    float: left;
    border-radius: 6px;
    background:linear-gradient(to left, lightgrey, #ededed);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1);
    padding-bottom: 20px;
    width: 175px;
    margin-left: -100%;
    position: relative;
    left: -197px;
}
main aside nav li {
    line-height: 2rem;
}
main aside nav li:first-child,main aside nav li a{
    padding: 10px 15px;
    display: block;
}
main aside nav li a.active,main aside nav li a:hover {
    border-left: 3px solid brown!important;
    background: #efefef;
    padding-left: 15px;
    margin-left: -3px;
}
main article div {
    min-width: 100%;
    min-height: 700px;
    margin: auto;
    border: none;
}
main article footer p {
    text-align: center;
}